iPhone 5s Battery
@lmusolino of course you can skip those steps (9-12) but it's risky for those digitizer to be damaged if you are careless while removing the battery.
My iphone looses charge quickly, at 30% it will totally shut down due to low charge. This guide save me from upgrading my iphone, I believe that iphone should lasts for 4-5 years before upgrading, upgrading the battery pack will give extra 2 years for iphone in my opinion, I just followed the video here, before you try to remove the adhesive from the battery, use first a hair dryer at the back of the phone, enough heat only till you can feel discomfort, heating it too much might risk for battery explosion. It is evident that the heat applied causes the battery to bent when you successfully removed the battery.
Those screws i used a 4 different color of marker pen, I marked all that hole plus the screws, in case they will be mixed up it will be easy to sort out.
I used a i-Slacker also, i dont want to take chances damaging the home button when prying it up. I-slacker did it perfectly.
Proceed with caution, if you are not confident, watch the video many times, and read all the comments here. It helps a lot.